Particles move perpendicular to the direction of energy transferCrest - Top of the WaveTrough - Bottom of the waveWavelength - Measure from one point on one wave to the same point on the next waveAmplitude - Height of a wave measured from rest positionSpeed depends on the mediumEnergy is proportional to the square of the amplitudeLinks:Simulation -Wave on a String from PhET
Particles vibrate parallel to the direction energy is transferredCompression - Particles closer togetherRarefaction - Particles more spread outSpeed of the wave depends on the medium and not on the amplitudeLinksSimulation - Wave Interference at PhET
Almost all sounds we hear are composed of multiple frequencies interfering with one anotherUse Audacity to analyze a sound for its component harmonicsUse the Generate Tone function to reproduce the component frequenciesAudacity is free and is available for Windows, OS X, and Linux
InterferenceTwo waves or pulses in the same place at the same time combine and appear to be a single wave or pulse. The waves continue on unchanged by the interaction in the direction of propagation (i.e. the direction they were traveling).Constructive interference happens when the resulting amplitude is larger.Destructive interference happens when the resulting amplitude is smaller. In some cases there is Complete Destructive interference where there is no sign of a wave or pulse passing.